A power of attorney needs the principal’s signature to exist at all, and in almost every real-world situation it also needs a notary. Depending on your state and whether the document covers finances or healthcare, you may also need two witnesses, and the person you’re naming as agent may need to sign an acceptance before using the document. So the short answer to who needs to sign a power of attorney is: the principal, usually a notary, often two witnesses, and in many cases the agent.
Here is what each of those signatures does, when you can skip one, and when skipping one will get your POA rejected at a bank or recorder’s office.
The Principal
The principal is the person granting authority, and this signature is the one requirement every jurisdiction agrees on. Under the Uniform Power of Attorney Act, a POA “must be signed by the principal or in the principal’s conscious presence by another individual directed by the principal to sign the principal’s name.”1Uniform Law Commission. Uniform Power of Attorney Act Without it, the document has no legal effect no matter how many other people sign.
A principal who cannot write their full name can use a mark such as an “X” to indicate intent. The mark carries the same weight as a written signature when made with clear purpose. Some states require additional witnesses when a mark is used in place of a full signature, so check local rules before relying on it.
Mental Capacity at the Moment of Signing
The principal must understand what the POA does and what powers are being handed over. The bar is generally contractual capacity, meaning the principal needs to grasp the nature and consequences of the document in the same way they would need to understand a contract. That is a higher standard than what is required to sign a will.
In practical terms, the principal should understand three things: what a power of attorney is, which specific powers are being granted, and what property or decisions will be affected. The assessment looks at the principal’s understanding at the exact moment of signing, not their general condition. Someone with early-stage dementia might have capacity on a good day; someone with advanced cognitive decline almost certainly would not.
If capacity is later questioned, the burden usually falls on whoever is challenging the document. Courts look for evidence of confusion, coercion, or impairment at the time of signing, which is where a notary and witnesses pay off: they can testify that the principal appeared aware and acted voluntarily.
Signing by Proxy When the Principal Cannot Write
When a principal has full mental capacity but a condition like paralysis, severe arthritis, or advanced Parkinson’s disease prevents them from signing, another person can sign the principal’s name at the principal’s explicit direction. This is called a signature by proxy, and the proxy must sign while physically present with the principal.1Uniform Law Commission. Uniform Power of Attorney Act
Proxy signatures typically follow a specific format to make the arrangement visible on the document itself, such as “John Doe, signed by Jane Smith at the direction of the principal.” Both the notary and any witnesses present must observe the principal giving the direction. Witness requirements for proxy signatures vary: some states require two disinterested witnesses in addition to the notary, others require only one, and a few require none beyond the notary. The proxy signature carries the same authority as if the principal had signed personally, but only when state formalities are followed.
The Notary Public
A notary verifies the identity of the signers, confirms they appear to be acting voluntarily, and signs and stamps the document to create an official record. Under the Uniform Power of Attorney Act, notarization is not technically mandatory for every POA, but it creates a legal presumption that the principal’s signature is genuine.1Uniform Law Commission. Uniform Power of Attorney Act That presumption shifts the burden to anyone challenging the document.
Even where notarization isn’t strictly required by statute, it becomes functionally mandatory in several common situations:
- Real estate transactions. A POA used to buy, sell, or transfer property almost always needs to be notarized before it can be recorded with the county recorder’s office.
- Banking and financial institutions. Most banks will refuse to honor a POA that hasn’t been notarized, regardless of what the statute technically allows.
- Out-of-state use. A notarized POA is far more likely to be accepted across state lines, since notarization makes the document self-authenticating.
The notary checks each signer’s identity through government-issued identification, completes an acknowledgment section, signs, and affixes an official seal. Notary fees are regulated by state law and typically range from $5 to $15 per signature, though remote online notarization fees run higher in many states.
If the principal doesn’t have a current government-issued photo ID, many states allow the notary to rely on a credible identifying witness instead. That witness must personally know the principal, swear under oath to the principal’s identity, and generally have no financial interest in the document.
Witnesses
Whether you need witnesses depends on your state. The Uniform Power of Attorney Act itself does not require witnesses for a financial POA, relying on notarization to validate the signature. A number of states that adopted the Act added their own witness requirements on top of the model language. Connecticut, for example, requires two witnesses in addition to notarization.
Where witnesses are required, most states mandate two, and they generally need to be disinterested. A good witness should not be:
- The person named as agent or successor agent
- A relative of the principal by blood or marriage
- Someone who stands to inherit from the principal
- Anyone who would financially benefit from the powers being granted
Witnesses typically must watch the principal sign in real time, then sign their own names in a witness attestation section that usually includes printed names and addresses. Their signatures confirm that the principal appeared to be of sound mind and was not being pressured. If the POA is later challenged, witnesses can be called to testify about what they observed.
Even in states where witnesses aren’t legally required for a financial POA, having them present adds a layer of protection that costs nothing. If there’s any chance the principal’s capacity could be questioned later, witnesses are cheap insurance.
The Agent
The person being appointed as agent, sometimes called the attorney-in-fact, doesn’t always need to sign the POA for it to be valid. But many POA forms include an acceptance section, and some states require the agent to sign before exercising any authority. Under one common version of the Uniform Power of Attorney Act, a person accepts appointment “by exercising authority as an agent or by any other assertion or conduct indicating acceptance.” Some state versions go further and require the agent to execute a written acknowledgment of their duties before acting under a durable POA.
By signing an acceptance, the agent confirms they understand they owe fiduciary duties to the principal: acting in the principal’s best interest, avoiding self-dealing, keeping the principal’s assets separate from their own, and keeping records of transactions. The acceptance section typically requires the agent’s signature, printed name, and date.
There is no universal deadline for the agent to sign after the principal executes the POA. Some agents sign on the same day; others don’t sign until they actually need to use the document, which could be years later. The critical point is that the agent must accept before attempting to act. A bank or title company that sees an unsigned acceptance section will likely refuse to honor the POA until the agent completes it. Many people have the agent sign at the same time as the principal to avoid later friction.
Extra Signing Rules for a Healthcare POA
A healthcare POA, sometimes called a healthcare proxy or medical power of attorney, often has stricter signing requirements than a financial POA. The biggest difference is who can serve as a witness. Most states bar certain categories of people from witnessing a healthcare POA:
- Healthcare providers. The principal’s doctor, nurse practitioner, dentist, or psychologist typically cannot witness.
- Facility employees. If the principal lives in a nursing home or assisted living facility, employees and operators of that facility are generally disqualified.
- The named agent. The person being appointed to make healthcare decisions cannot also serve as a witness.
- Relatives. People related to the principal, the agent, or the successor agent by blood, marriage, or adoption are usually excluded.
Some states impose even more specific requirements for residents of skilled nursing facilities. In those situations, a long-term care ombudsman may need to serve as one of the witnesses, adding independent oversight for a particularly vulnerable population.
Notarization rules for healthcare POAs also differ from financial POAs. Several states accept either notarization or witnesses for a healthcare POA but don’t require both. A few states don’t require notarization for healthcare documents at all. Because the rules vary so much, the safest approach is to both notarize the document and have two qualified witnesses sign, which satisfies the requirements in every state.
Electronic Signatures and Remote Online Notarization
The federal E-SIGN Act validates electronic signatures for most types of documents but specifically excludes wills, codicils, and testamentary trusts. Powers of attorney are not categorically excluded under the federal law, though individual states may require traditional ink signatures depending on the type of POA. Some state versions of the Uniform Power of Attorney Act define “sign” broadly enough to include attaching an electronic sound, symbol, or process to a record with the intent to authenticate it.
Remote online notarization has expanded rapidly, with roughly 38 states now authorizing it. During a session, the principal and notary connect through a live audio-video platform. The notary verifies the principal’s identity through knowledge-based authentication questions and credential analysis, then watches the principal sign electronically. The session is recorded and archived, and the notary applies a digital seal that can be independently verified and shows evidence of tampering.
Remote notarization can be useful for principals with mobility limitations or those executing a POA across state lines. Not every institution accepts remotely notarized documents yet, however, and some real estate transactions still require ink-on-paper execution. Confirm acceptance with the institution before you rely on it.
If a Bank or Institution Refuses Your Signed POA
Even a properly signed and notarized POA sometimes gets rejected at the counter. Banks have historically been cautious about POAs due to fraud concerns, and individual employees may not understand the document. Under the Uniform Power of Attorney Act, a third party presented with a properly acknowledged POA must either accept it or request a certification or legal opinion within seven business days. Once they receive whatever additional documentation they requested, they have five more business days to accept the POA. They cannot require you to use their own proprietary form instead.
If an institution unreasonably refuses a valid POA, the agent can petition a court to compel acceptance, and the institution may be held liable for attorney’s fees and costs. A third party can still legitimately refuse a POA if they have a good-faith belief that the principal lacked capacity, the document has been revoked, or the agent is acting beyond the scope of their authority.
The best way to avoid rejection is to make sure every signature block is properly completed, the document is notarized, and the agent can present either the original or a certified copy. Having the agent sign the acceptance at the time of execution, rather than waiting, tends to raise fewer questions down the line.